[v3] Small tweak to std::move_if_noexcept

[Paolo Carlini]

Hi,

noticed while working on std::vector. Tested x86_64-linux, committed.
Paolo.

///////////////////

2011-06-06  Paolo Carlini  <paolo.carl...@oracle.com>

        * include/bits/move.h (move_if_noexcept): Use __and_ and __not_.

Index: include/bits/move.h
===================================================================
--- include/bits/move.h (revision 174699)
+++ include/bits/move.h (working copy)
@@ -90,8 +90,8 @@
    */
   template<typename _Tp>
     inline typename
-    conditional<(!is_nothrow_move_constructible<_Tp>::value
-                && is_copy_constructible<_Tp>::value),
+    conditional<__and_<__not_<is_nothrow_move_constructible<_Tp>>,
+                       is_copy_constructible<_Tp>>::value,
                 const _Tp&, _Tp&&>::type
     move_if_noexcept(_Tp& __x) noexcept
     { return std::move(__x); }